President Donald Trump will travel to Billings, Mont., on Thursday for a "Make America Great Again" rally. Photo by Alex Edelman/UPI | License Photo

Sept. 6 (UPI) -- President Donald Trump will travel to Montana on Thursday evening as members of his administration scramble to prove they weren't behind a New York Times op-ed describing a resistance within the White House.

It will be the president's second visit to the state in two months. He traveled to Great Falls in July to support state Auditor Matt Rosendale in his bid to unseat Sen. Jon Tester, D-Mont.

This time, Trump is expected to rally his Republican base in Billings, and likely take some swipes at Wednesday's anonymous op-ed in the process.

The article, headlined "I am part of the resistance inside the Trump administration," lays out efforts by a senior administration official -- and others in the White House -- to "frustrate parts of [Trump's] agenda and his worst inclinations."

The official distances themselves from a liberal effort to resist Trump, saying they want Trump's administration to succeed.

"But we believe our first duty is to this country, and the president continues to act in a manner that is detrimental to the health of our republic," the author of the article wrote.

It comes one day after details from journalist Bob Woodward's book, Fear: Trump in the White House, were revealed, portraying a White House in turmoil, with staffers stealing documents off Trump's desk and attempts to suppress some of the president's more incendiary ideas.

"Does the so-called 'Senior Administration Official' really exist, or is it just the Failing New York Times with another phony source? If the GUTLESS anonymous person does indeed exist, the Times must, for National Security purposes, turn him/her over to government at once!" Trump tweeted Wednesday evening after the op-ed was published.

Earlier in the day he hinted at possible treason with a single-word tweet.

"The Deep State and the Left, and their vehicle, the Fake News Media, are going Crazy - & they don't know what to do. The Economy is booming like never before, Jobs are at Historic Highs, soon TWO Supreme Court Justices & maybe Declassification to find Additional Corruption. Wow!" he wrote Thursday.

As pundits scramble to figure out who's behind the New York Times article, so too is the White House.

"The individual behind this piece has chosen to deceive, rather than support, the duly elected president of the United States," White House press secretary Sarah Sanders said Wednesday. "He is not putting country first, but putting himself and his ego ahead of the will of the American people. This coward should do the right thing and resign."

House Speaker Paul Ryan, R-Wis., echoed the call for a resignation during his weekly news conference Thursday.

"The person who works in the administration serves at the pleasure of the president. It's a person who obviously is living in dishonesty," he said. "It doesn't help the president. If you're not interested in helping the president, you shouldn't work for the president, as far as I'm concerned."

A senior White House official told CNN that denial statements by top administration officials are being printed out and delivered to Trump.

Vice President Mike Pence also has denied his involvement in the op-ed after the use of a unique word -- lodestar -- came under scrutiny. It's an unusual word Pence has used multiple times in speeches, and one that shows up in the Times op-ed.

"We may no longer have Senator [John] McCain. But we will always have his example -- a lodestar for restoring honor to public life and our national dialogue. Mr. Trump may fear such honorable men, but we should revere them," the op-ed reads.

A communication official in Pence's office, Jarrod Agen, said the second-in-command wasn't behind the essay.

"The Vice President puts his name on his Op-Eds. The @nytimes should be ashamed and so should the person who wrote the false, illogical, and gutless op-ed. Our office is above such amateur acts," he tweeted.